You need to iterate over your ResultSet calling next()
.
This is an example from java2s.com:
DatabaseMetaData md = conn.getMetaData();
ResultSet rs = md.getTables(null, null, "%", null);
while (rs.next()) {
System.out.println(rs.getString(3));
}
Column 3 is the TABLE_NAME
(see documentation of DatabaseMetaData::getTables
).